Brush structure with parallel flakes



April 22, 1947.

A. c. KQRTE BRUSH STRUCTURE WITH PARALLEL FLAKES Filed Sept. 4, 1943 FIG.1.

ALFRED KORTE BY z g xfrrr.

Patented Apr. 22, 1947 mm STATES PATENT OFFICE 2,419,356 BRUSH STRUCTURE WITH PARALLEL FLAKES Alfred C. Korte, St. Louis, Mo., assignor to Carter Carburetor poration of Delaware Corporation,

St. Louis, Mo., a cor- Application September 4, 1943, Serial No. 501,318

6 Claims.

graphite flakes.

It is the main object 01 the present invention to provide means for preventing sticking of the brush in the brush carrier due to swelling caused by immersion oi the brush in gasoline fuel.

It is another object to provide a brush in which the swelling tends to compensate for the normal wear of the brush in service.

These objects and other more detailed objects hereafter appearing are attained by the structure and method disclosed in the attached drawing, in which:

Fig. 1 is a side view, partially sectioned, illustrating an electric fuel pump for operation submerged in a fuel tank and embodying the invention.

Fig. 2 is an enluarged view of the novel brush with the flake arrangement illustrated diagrammatically.

The pump device illustrated comprises an electric motor enclosed within a housing 5 and having is depending shaft 6 to the lower extremity of which a centrifugal impeller 1 is attached. The pump casing 8 is attached to the motor casing by radial ribs, one being shown at 9, and the unit is supported in the fuel tank by means of a rigid tube It which also serves as the outlet. for the pumped fuel. This pump is fully de scribed and claimed in the above-mentioned patent and in a co-pending application of the present inventor, Serial No. 473,683, filed January 2'7, 1943.

An insulated brush casing ii is mounted in one of the ribs '9 with suitable relationship to a grounded brush (not shown). Slidable within casing H is a graphite brush i2 yieldingly urged rangement of the flakes, the brush ranged parallel to against commutator l3 by a coiled spring i4 compressed between the brush and a plug H5 at the outer end of the carrier casing.

The brush is formed of flaky graphite material with all ofiithe flakes arranged parallel to the ar cuate wearin'g surface [6 thereof. By this ar curs along the dimension C and tends to com sions A and B which would cause the same to stick in the carrier casing.

As an example of of eliminating the bad elfects of brush swelling,

Two of these brushes were then installed in a twenty-four volt electric fuel pump and run continuously for 917 hours immersed in fuel in the normal manner. It was then found that one of the brushes had neither increased nor de creased in length, while the wear on the other brush amounted to .0005". The normal wear of these brushes with the flakes arranged parailel to one of the sides of the brush, rather than to wearing surface, for the same period of time, was found to be .007. Accordingly, it was evident spects as will occur to those skilled in the art use of all modifications as come of the appended claims is new and the exclusive Within the scope templatecl.

I claim:

1. A brush for electrical machines a block of flaked material with the rial the wearing surface t 2. An electrical brush for operation is cm with liquid or moisture comprising flaked material susceptible to swelling la with the liquid or moisture, the flakes b ranged parallel to the wearing surface brush so that such swelling tends to com for the normal wear of the brush in seftl 3. An electrical brush comprising flakes pressed into a block with all the ranged parallel to the wearing surface.

flakes being arranged parallel to said commutator engaging surface whereby swelling of the graphite tends to compensate for normal wear of the brush.

6. In an electrical machine for operation immersed in liquid, 5 brush mounting, a commutator, and a. brush of flaky graphite supported in said mounting with the flakes thereof arranged parallel to the brush surface engaging said commutator whereby swelling oi the graphite due to 5 contact with the liquid occurs only in the direction normal to said surface.

C. KORTE.

REFERENCES CITED The following references are of record in the tile of this patent:

Number UNITED STATES PATENTS Name Date Holmes Sept. 6, 1892 Henry Oct. 13, 1925 

